Magneto impulse-starter.



B. LAWRENCE.

MAGNETO IMPULSE STARTER.

APPLICATION FILED NOV. 12. 191B.

Patented Feb. 11, 1919.

BENJAMIN LAWRENCE,

QF LEYTDN EHGLAEE'E.

IVIAGNETO IIvIPUISE-STARTEE.

Specification of Letters Patent.

Fateiited it, 1919,

Application filed November 12, 1918. Serial No. 262,169.

To all whom it may concern:

Be it known that I, BENJAMIN LAWRENCE, a subject of the King of England, residing in Leyton Essex, l lngland have invented. certain new and useful Improvements in Magncto Impulscfitarters, of Which the following is a specification.

This invention relates to magneto impulsedeviees for starting; purposes, and a primary object is to provide an improved construction of apparatus of the kind wherein a driving-member for connection to the engine-shaft is connected to a driven-member for-connection to the magneto-shaft through a spring, and a movable part of the drivenmember cooperates with a stationary stop to hold the. driven-member back until the spring is loaded, when the said catch is automatically tripped; the catch may further operate under centrifugal control as a positive driving-element between the driving and driven members when the starter is running at speed.

It is well-known that the object of these devices to enahle the magneto-armature to have a rapid angular movement given to it when the engine is being only slowly cranked around so that an eiiieient spark may be produced notwithstanding the slow movement of the engine-shaft.

In a magneto impulse-starter according to this invention, the driven-member enters the driving-member and the catch is mounted on the driven-member with its operative end projecting through a slot in the drivingmember to engage a stationary stop disposed outsid the circumferential sweep of the driving-member in such manner that when the catch at one end of the slot it engages the said step, hut when the further move-. ment of the drivin -member brings the other end of the slot against the operative end of the catch the said catch is thereby disengaged from the stop.

The invention consists in the construction, an'angen'ient and combination of parts described hereinafter and pointed out in the claims.

One embodiment of the invention is illustrated by way of example in the accompanying drawings, wherein 2* Figure 1 is a section through the apparatus in the plane of. the axis of rotation;

Fig. 2 is a section taken on the line 2-2 in Fig. l

The driving-member A is cup-shaped, the

walls A forming the cup being slotted at A and having-on the non-slotted portions progections A The member A is provided with a central tongue 21* whereby it can be secured to the driving-shaft. The drivenmemb er B comprises a hub having a jaw B engaging with a corresponding couplingelement on the magneto-spindle, and a flange B the periphery of which is recessed at B to receive the projections A on the Walls A of the member A. ihe hub of the member B extends axially into th cup-shaped member A and is surrounded at its end by. one or more fiat spiral springs O, the inner end of which is secured to the hub B and the outer end to a part C fast on the inner face of the walls A of the member A; At the side of the spring and still within the cup-shaped member is a disk D which is, fast on the hub of the member B or is held in rigid relation thereto by screws D which extend through the disk D into the flange B Between the disk and flange studs D are carried, and on each stud is mounted a catch E having an operative end E and a weighted tail portion E Sliding radially in a guide F on the'disk D are two spring controlled detents F. These are situated on opposite sides of the boss B and engage recesses in the walls A of the cup-shaped member A. Auxiliary detents F free to float in their supports engage the sides of the detents F and have their outwardly projecting ends in proximity to the catches E. The detcnts F are notched on the side toward the flange l 2 as also ar the guides F and bars F he one across each detent and 100 in the notches in the guides. The bars hold the detents in against undue displacement endwise and are themselves kept in place by the screws 1) and the flange B.

To keep the=members A and B in aline- 105 merit a pin A is made fast in the member A and projects into the boss B. A set-screw B in the boss abuts against the end of the pin A and thus spaces 'thesetwo members 7.

apart. The two members are thus inelosed i."

in a casing G, G G comprising a main body-portion G having a foot G whereby the whole mechanism can be secured to a suitable support, and a detachable plate G Ball-bearings G ar provided between the main body G of the casing and the driving member A and between the detachable plate and the driven-member B.

in the top of the casing G is a stationary i stop H. This is secured in place by screws 5 and projects through the casin intoproximity to the exterior of the driving member A. One side of the projecting por tion of the' stop has a face set at such an angle as to arrest the operative end E of either of the catches E, and the other side of the projection has a face H which is so sloped that it will not arrest the catches even though the stop be-turned around to bring this face into the position of the face The operation of this apparatus is as follows c As the engine-shaft, which is secured to the driving member A, is slowly turned around by the crank-handle, the member A first carries with it the driven member B because of the interconnecting detents F. This movement, which is in the direction of the arrow in Fig. 2. continues until the operative end E of one of the catches E is brought against the face H of the stop H. The weighted tails E of the catches insure that when turningthe handle slowly the operative ends of the catch will lie in the path of the stop H. The driven member B is thus arrested, and consequently the detents, whose ends are rounded, are forced out of engagement with the wall A of the driving member. The continued angular movement of the member A, therefore, will now load the spring 0 which connects the members A and B until the end of the slot A through which the operative end of the catch projects, is reached, when the wall A of the member A will strike the operative end of the catch and drive it inward so that it is released from the stop H. This tripping of y the catch E causes the member B to be suddenly rotated relatively to the member A by means of the spring, which quick movement communicated to the magneto-spindle produces the required spark. The forward movement of the member B is arrested by the projections A on the member A. operating in the recesses B? in the flange B and when so arrested the detents F are once more in line with the recesses for them in the walls A- of the member-A, so that they once more see the engineshaft and the magneto is now maintained through the spring or springs O and the detents F.

It not desirable to drive through the yieldingcontrol-spring C only at any time, and therefore it is necessary to insure that the engagement of the dctents shall be suiticient to keep the driving and driven parts interlocked. Lest therefore they should jerk out of place, the auxiliary detents F are provided; these act ordinarily merely as floating pins between the detents F and the catches E, being easily brushed aside when the detents are forced back, but they can nolonger float when the catches are moved in by centrifugal force, as the catches then abut against the ends of these pins and hold them in against displacement.

The beveled iace H. on the stop H assists the passing of the catches E if the engineshaft is at any time turned in the wrong direction, but it is also provided for throwing the device out of action, as by reversing the iock, that is turning the stop through an angle of 180, so that when the face H is brought to the position occupied by the face H the catches are prevented from being arrested by the stop. Throwing the device out of action could also be effected by making this stop adjustable radially.

Instead of theauXiliary detents F the tail ends of the catches may be so shaped that when they swing outward they engage cooperating recesses in the driving member A and these operate as pawls, whereby a positive drive is effected, springs being provided to move the catches out from this locking position when the speed is reduced.

it will be seen that the same wei hting of the tail-ends of the catches which serves to bring their operative ends out of the path of the stop at high speeds, serves to bring them into the path of the stop at low speeds.

It will be appreciated that when the magneto impulse-starter is arranged as described and illustrated, it constitutes a selfcontained unit which can be interposed between the engineshaft and the magnetospindle without diihculty, as the jaw B of the member B can engage a correspondingly shaped tongue on the spindle and the tongue on the member A. can engage a c0rrespondingiy shaped j aw on the engineshaft; the foot G of the casing afiords simple means whereby the device can be rigidly se cured in position after connection with the engine-shaft and magneto-spindle. i

in some cases it may be preferred to dispense with the yielding detents F and their auxiliary detents F, as these are not essen tial, because the initial movement given by the engine-shaft necessary to bring the ends E of the catches into operation would still take place through the connecting springs C. and the positive drive would be effected by means of the tail-ends of the catches engaging the driving-member A under centrifugal action as already described.

What I claim as my invention and desire to secure by Letters Patent is V 1. In a magneto impulse-starter of the kind described, the combination with a driving member having a slot in the periphery thereof, a driven member having a portion entering axially into the driving member, and a spring operatively connecting the driving member toth'e driven member, of a stop fixed outside the circumferential sweepof the driving member, and a catch mounted on the driven member, one operative end of the said catch normally projecting through said slot and being adapted to abut against said stop at one end of the slot when the driven member is rotated by the driving member through the medium of said spring, and to be released therefrom by the other end of said slot during the further movement of the driving member.

2. In a magneto impulse-starter of the kind described, the combination with a driving member having a slot and a recess in the peripherythereof, a driven member having a portion entering axially into the driving member, and having a projection taking into said recess for limiting the relative movement of said members, and a spring operatively connecting the driving member to the driven member, of a stop fixed outside the circumferential sweep of the driving member, and a catch mounted on the driven member, one operative end of said catch normally projecting through said slot and being adapted to abut against said stop' at one end of the slot'in one'angular position of the driving member and to be released therefrom by the other end of said slot in another angular position of the ing member.

In a magneto impulse-starter of the kind described, the combination with a driving member having a slot in the periphery thereof, a driven memberhaving a portion entering axially into the driving member, and a spring operatively connecting the driving member to the driven member, of a stop fixed outside the circumferential sweep of the drivin member, a catch mounted on the driven member,one-operative end of the said catch norma'ily projecting through said slot and being adapted to abut against said stop at one end of the slot when the driven member is rotated by the driving member through the medium of said spring, and to be released therefrom by the other end of said slot during the further movement of the driving member, and a spring-pressed detent guided on the driven member and normally engaging the driving member.

4-. In a magneto impulse-starter of the kind described, the combination of a driving member having a slot in the periphery thereof, a driven member having a portion entering axially into the'driving member, a spring operatively connecting the driving member to the driven member, a guide fixed on the driven member, a spring-pressed detent guided by said guide and normally engaging the driving member, an auxiliary detent'slidable in said guide and adapted to lock said spring-meshed detent in its engaging position, a stop'fized "outside the cir cumferential sweep of the driving member, and a catch mounted on the driven member, one operative end of said catch normally projecting through said slot and being adapted to abut against said stop in one angular position of the driving member and to be released therefrom in another angular position of the driving member relatively to the driven member, the said operative end of the catch in its released position being arranged to coact with the said auxiliary detent and hold the same in its locking position.

5. In a magneto impulse-starter of the kind described, the combination of a driving member having a slot in the periphery thereof, a driven member having-a portion entering axially into the driving member, a spring operatively connecting the driving member to the driven member, a casing surrounding said members, a stop having two opposed faces detachably and reversibly fixed in said casing outside the circumferential sweep of.

the driving member, and a catch mounted on the driven member, one operative end of said catch normally pro ecting through said slot and being adapted to abut against said.

step at one end of the slot, and to be released tlr-u'efroin by the other endof said slot during relative rotation of the said members.

In testimony whereof I aihx my signature.

BENJAMIN LAWEE) NCE. 

